In Thomason Patents, such as U.S. Pat. Nos. 3,145,707 and 3,215,134, the low-cost open-flow (trickle-flow) solar collector brought about low-cost solar heat collection. Many solar heated homes used that simple basic invention.
Quality was improved and high efficiency was achieved by the invention disclosed in Thomason U.S. Pat. No. 3,989,031. Panels embodying that invention were placed on the market under the trade name of Thomason "SOLARIS".
And yet, improvement and lower cost could be achieved. The thin aluminum frame (illustrated at 6 in U.S. Pat. No. 3,989,031) and the gasket seal (illustrated at 7) have been eliminated with a considerable reduction in cost.